High-pressure valve.



J. FOSTER.

HIGH PRESSURE VALVE.

APPLICATION man 'Aus.22. 1912.

1,147,157, Patented July 20, 1915.

I. r l 8/ 0 n as er W 4 $146 JOHN Eos'rER, 0 MONTREAL, QUEBEC, CANADA.

HIGH PBESSURE VALVE.

Specification of Letters Patent.

Patented July 20, 1915.

Application filed August 22, 1912. Serial No. 716,523.

T 0 all whom it may concern:

Be it known thatl, JOHN FOSTER, of th city of Montreal, in the Province of Quebec and Dominion of Canada, have invented certain new and useful Improvements in High- Pressure Valves, of which the following is a full, clear, and exact description.

This invention relates to improvements in high pressure valves and is especially designed to be used for discharging the pulp from digester tanks under high pressure.

The object is to provide a smooth and easy operating valve of the balanced type, so that all danger of blow-outs is eliminated.

A further object is to provide a valve,

the fluid tight qualities of which are always by a similar cap 5. The cap 5 is provided with a neck 6, through which the valve stem passes and to the upper end of which a stuffing box 7 is secured. The neck 6 is internally screw threaded, as indicated at 8. The valve itself comprises a pair of enlargements or pistons 11 and 12 respectively, formed integral with and connected together by a short piston rod 13. These pistons include split sleeves or rings 14 and 15, respectively, let into circumferential or annular recesses therein and of such size that they require to be slightly compressed to allow 01": the insertion of the pistons into the bore ofthe body. The sleeves 14 and 15 are held in place on the pistons by flanges 16 at adjacent ends of the pistons and by cover plates 17 and 18 respectively at the remote ends of the pistons. The upper pis ton 11 is shorter than the lower piston 12, as is clearly seen in the drawing, the reason for this being that the lower piston 12 requires additional length to out ofl communication between the inlet and outlet, and yet have suiflcient bearing surface above and below the passage of communication to form a fluid tight joint. The lower cover plate 18 is secured to the piston 12 preferably by piston against rotation.

means of screws 19, and is provided with diametrically opposite projecting pins 20 which engage in grooves 21 formed in the lower portion of the body and thus hold the A headed pin 28 projecting from the piston 12 of the valve, through the split 29 of the sleeve 15, prevents the sleeve 15 from rotating or from collapsing under fluid pressure, and also holds it in position when the cover plate 18 is removed.

A valve stem 9 having screw threads 10 cooperating with the threads 8 of the cap 5 is provided at its upper end with a hand wheel 27 and has its lower flanged end 22 secured within the recess 23 in the piston 11 by means of a hollow screw plug or nipple 2a.

While the drawings for sake of convenience do not illustrate the split in sleeve 14 or show the piston 11 provided with a pin 28, it is to be understood that the sleeves and pistons are in actual practice identical in these particulars.

When the valve is in open position as shown in the drawing, it is obvious that there is a clear passage between the inlet and outlet necks 2 and 3. The only obstruction in this passage is the cylindrical rod 13 which, however, owing to its curved sur face and the large space in which it is located, offers little or no resistance to flow. lVhen the valve stem 9 is rotated, it rises by reason of the screw thread engagement with the cap and draws up with it the valve, which is held against rotation by the pins 20 engaging in the slots 21. This upward movement of the valve eventually brings the lower piston 12 between the inlet and outlet passages, so that communication through the valve is cut oil". If there is any leakage of fluid under pressure around the sleeves 14 and 15, the fluid passes through the splits 29 into the interior of the sleeves, so that the pressure on the inside and outside of the sleeve is equal and the effective expansive force of the ring is not detracted from. The fluid pressure against the adjacent ends of the piston is in opposite direc tions, so that the valve opens or closes with equal ease, regardless of the fluid pressure. Furthermore, the fluid pressure being equal in opposite directions, there is no tendency to blow off one or other of the caps and eject the valve at high velocity with disastrous results.

Having thus described my invention, what I claim is 1. A high pressure valve comprising a casing having alining inlet and outlet passages, a piston valve having spaced enlarged portions adapted to reciprocate in said casing, said portions terminating at their adjacent ends in lateral flanges and having cover plates at their remote ends, resilient sleeves fitting about said enlarged portions between and held in place by said flanges and cover plates, one of said sleeves being split, means for preventing the rotation of said split sleeve, grooves formed in said casing, and pins carried by said piston valve working in said grooves.

2. A valve of the type described, including a casing having alining inlet and outlet passages and a piston-valve arranged Within said casing and having piston-forming enlargements working in said casing above and below respectively, the uppermost portion of said inlet and outlet passages, said piston-enlargements being fitted with resilient sleeves, let into annular recesses in action of the contained fluid.

In witness whereof I; have hereunto set my hand in the presence of two Witnesses. JOHN FOSTER. Witnesses:

STUART R. W. ALLEN, G. M. MORELAND.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patent:

Washington, D. G. 

